The inverter is a DC to AC transformer, which in fact is a voltage inversion process with the converter. The converter converts the AC voltage of the power grid into a stable 12V DC output, while the inverter converts the 12V DC voltage of the adapter output to high-frequency alternating current, and the two parts also use a much more pulse width modulation (PWM) technique. Its core is a PWM integrated controller, adapter with the UC3842, the inverter uses the TL5001 chip.
The operating voltage range of the TL5001 is 3.6~40v with an error amplifier, a regulator, an oscillator, a PWM generator with dead-zone control, a low-voltage protection circuit, and a short-circuit protection circuit. Input Interface section: input part has 3 signals, 12V DC input vin, working enable voltage ENB and panel current control signal Dim. Vin is provided by adapter, the ENB voltage is provided by the MCU on the motherboard, the value is 0 or 3V, when the enb=0, the inverter does not work, while the enb=3v, the inverter is in normal operation, and the dim voltage is provided by the motherboard, the change range between 0~5v,
The different dim values are fed back to the PWM controller feedback side, and the inverter provides a different current to the load, the smaller the dim value, the greater the current of the inverter output.
Voltage start-up circuit: ENB for high power, output high pressure to light panel backlight lamp.
PWM controller: The following functions are composed of: Internal reference voltage, error amplifier, oscillator and PWM, overvoltage protection, undervoltage protection, short circuit protection, output transistor. DC Transformation: A voltage conversion circuit consisting of a MOS switch tube and a energy storage inductor, the input pulse is amplified by a push-pull amplifier to drive the MoS tube to make a switching action, allowing the DC voltage to charge and discharge the inductor, so that the other end of the inductor can get the AC voltage.